The present invention is directed to educational blocks of the type which include replaceable faces which are secured in recesses on the face of the blocks. The removable faces (or chips as they are called in this specification and claims) serve two main purposes. First of all, they enable structures to be created by utilizing a common chip to secure two blocks together. A second advantage of having a block with replaceable faces is that a single block with replaceable faces can enable a block to be provided with a larger number of symbols, such as letters and numerals, on its faces.
A patent which is representative of the prior art is U.S. Pat. No. 1,895,611 to Doak, entitled Building Blocks. A significant disadvantage of the blocks disclosed in the Doak patent is that it is difficult to remove the replaceable faces of the block. Furthermore, the configuration of the Doak block does not provide a block with a weight to strength ratio that is as acceptable as the weight to strength ratio of the block of the present invention.
Accordingly, an object of the present invention is to provide an educational building block with a weight to strength ratio that is superior to prior art blocks.
A further object of the present invention is to provide a building block with replaceable faces in which the replaceable faces can be removed with greater facility than similar prior art blocks.